This invention relates to a mineral mining installation and in particular to an installation for winning material in the "stable-hole" regions at the two ends of a longwall face.
Winning of coal from a longwall face adjoining a roadway gallery has always been difficult since the known type of coal plough which is guided on a longwall conveyor can only remove coal between the two end drive stations of the conveyor. The portions of the longwall face which accommodate the drive stations (that is to say the so-called "stable-hole" regions) must, therefore, either be won by hand or by auxiliary winning machines. Moreover, as these drive stations are heavy and bulky the "stable-hole" regions must necessarily be won as a preliminary operation before the main portion of the face can be won.
One known type of winning machine for these "stable-hole" regions is an auxiliary plough which is driven from the main plough via push rods. The disadvantage of such an arrangement is that the main plough must be stationary during operation of the auxiliary plough, and so the main mining operation is interrupted each time the "stable-hole" regions need to be excavated further prior to the conveyor (and drive stations) being advanced to a position in which a newly exposed portion of the longwall face can be cut. This inevitably results in a reduction in the productivity of such an arrangement.
Another known type of auxiliary plough utilises its own drive unit. This plough is a combined cutter and loader having cutters alternating with ramp sections which function as loading devices for the cut coal. The plough is reciprocated along a guide by a double-acting ram. Unfortunately, this arrangement is costly and has a large overall width. Moreover, the interposition of the ramp sections between the cutters gives rise to problems. Furthermore, this type of plough cannot be used to cut out the "stable-hole" regions as a preliminary operation to the main cutting operation of the longwall face.
It is the aim of the invention to provide a plough for winning material in the "stable-hole" regions of a longwall face, which plough has its own drive units, is comparatively simple and sturdy and which has a comparatively small overall width.